Adjustable double log dog for sawmills



Jan. 28, 1958 R. Q, JUREK ADJUSTABLE DOUBLE LOG DOG FQR SAWMILLS FiledFeb. 21, 1956 2 Sheets-Sheet 1 Raymond C. Jurek INVENTOR.

BY Q4 I MMHM Jan. 28, 195 R. c. JUREK ADJUSTABLE DOUBLE LOG DOG FORSAWMILLS 2 Sheets-Sheet 2 Filed Feb. 21, 1956 Raymond G. Jurek INVENTOR.

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ww a 1 United States Patent ADJUSTABLE DOUBLE LOG-DOG FOR SAWMILLSRaymond C. Iurek, Virginia, Minn.

Application Februar-y 21,1956, SerialxNo. 566,943

This inventionrelatesin general: to new. and useful improvements insawmill constructions, ,and morev specifically to. anii'nprovedlog dogvassembly.

In order that a log may be retained in position during a sawingoperation, the head blocks are provided with suitable: log dogs forgripping the log. and retaining it? in position. The logdogs generallyinclude upper and lower dogs which are disposed in opposed relation: andwhich grip the. log therebetween. In. order to engage the log dogswith.the log,.it is necessary that the dogs be advanced or retractedaway froma knee of the headblock dependi'ng upon the diameter of the log and alsobe moved vertical. withrespect to each other to clampa log therebetween.Normally this isdone manually with the result that it is not onlytimeconsuming. but requires considerable work upon-the operator of thesawmill. In-fa'ct, most installations require the use of one manforoperating the sawmill and another man for operating. the log, dogs;

It is therefore theprimary object of this invention to provide. animproved. log dog assembly which includes; a fluid-cylinder. connectedto-the log dogs whereby by turne ing a. simple control handle theoperator of the sawmill may openor close the logdogs as desired withoutefliort out his part.

Another object of this invention is to' provide improved log dogassembly whichv includes an upper'dog: and a lower dog mounted formovement away from and towards: each other, there also being providedmeans connected to the log dogs which permits the simultaneous movementof the log dogs in and out together.

Still. another object of: this invention is to provide an improved logdog assembly which employs a-fluidl cylinder which is so constructedwhereby itrnay be easily attached to the knees of existing sawmills.

Afurther. object of this invention is toprovide an. improved log. dogassembly which has an extremely simple control. whereby a sawmilloperator may operate the log dog with amim'mum of effort so that oneperson may both set the log on the sawmill and operate the sawmill.

These together withother objects and advantages which will. becomesubsequently apparent reside in the. details of construction andoperation as more fully hereinafter described and claimed, referencebeing bad to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

Figure 1 is an elevational view of a head block of a sawmill and showspositioned thereon a log, the log being clamped on the head' block bymeans of the log dog assembly which is the subject of this invention;

Figure 2' is a front view of the log dog assembly removed from the headblock and shows the specific details thereof;

Figure 3 is a fragmentary elevational view similar to Figure 1 and showsthe upper log dog in an elevated position;

Figure 4 is anenlarged transverse vertical sectional view tional viewtaken substantially upon the plane indicated by thesection-line. 5=5of-FigureZ and shows further. the.details-of anoperator for movingthelog dogsint-and. out;.and

Figure. 6 (Sheet 1,) is an enlarged fragmentary verticalsectionalcviewtaken substantiallyupon'the planeindicated; by the section line 6:6. ofFigure-5. and. showsifurther the'detailsof the'operator for moving thelogdogs in and out.

Referring nowto Figure. 1, in particular,it will be seentha trthere is'illustrated.detailsofa sawmill which include; a head. block. 10?having adjustably mounted" thereon as knee:12.. Carriedibythe knee 12 isthelog dog assembly, which.-is?the subject ofi'thisiinvention thelogdogassembly beingreferred. to inageneral by therreference. numeral. 14;.The log: dogg'assembly 14-is illustrated. as gripping-a log 1T6andretainin'g it-iin-positiontontthe; head block 10;

The-log dog1assembly'14' includes a mounting bracket: whichisireferredto-in general by the reference numeral 18. The mountingbracket 18 is formed. Ofi avertical strap. 20" which has secured. to thelower end thereof a plate 22-. A similar plate-24 is securedto the upperends of the strap 20. The. strap 20 is'suitabliy'securedi tothe knee inthe position best illustrated in Figure 1..

Referring now" to-Figure-4 ill-particular, it will be seen that.theplates 2-2? and- 24: are provided: with: aligned slots 26 and 28,respectively; Slidahly received in the slots 26 and ls forz guidedmovement isa. slide bar 30'. The slide bar 30 1s vertically. disposed:and has secured to the upper' end thereof'. by means of. suitable:clamps 32 a cylinder 34 of a fluidmntor which isreferred' to in: generalby the. referencenumeral 36. Slidably" positioned withincylinder'3r4i'sa piston 38 which has eonnected thereto an elongated pistorc rod'40; Thepiston rod 40 passes through; a bore 42 in the upper platev 2 b and is:guided relative thereto;

In order that. the fluid. motor 36" may be controlled; there'isaprovidedavalive144'. The valve 44 hasconnected thereto an air line 46 (Figures1" and 3 whichmay be connected: tosany'desire'd compressed-supply;Extend ing: from the" valve 44':- and connected to opposite ends of thecylinder 343are:lines 48 and 50 The'valve 4'4 is provided withaisuitable handle-52 for operating the same. B'y selectively positioningthe handle 52, the piston- 38 is moved: up or down in the cylinder 34.

Securedto' the lower endof the slide bar 30forlimited movement:therewith is a lower dog assembly which is referred to'ii'n general bythe reference numeral 54. The lowerdog. assembly 54 includes a lowersupport 56' (Figure 4) which-is secured' directly to the slide bar30:Eittending: transversely through the lower support 56 is a lower dog58'. The dog 58 includes a rackportion' 59 (Figure 1.) to facilitateth'e positioning thereof.

Iournaled; in tlre pl'ates 22 and 24 is a vertically'ext'end ing: shaft:60.. Theshaft sods mounted for both rotation and vertical slidingmovement. Carried by the lower support 56 jounnalz block: 62 in:whichthe=1ewer end of the. shaft 60 is: journaled; Secured on the extremelower end of the shaft 60 is a gear 64 which is meshedwith the rack 60of the dog: 58; By rotating: the: shaft 60,, the rack. 59 is driven bythe gear. 64 with the result that. the. lower dog 58: is moved in: orout; asdesired with respect tothe. support. 56.

Slidably mounted on the slide. bar 30 intermediate. the plates 22 and;24 is an upper. dog, assembly which is referredto in general by the,reference numeral 66. The upper dog assembly 66 includes an uppersupport 68 which is g d 'figly positioned on the slide bar 30. se-

Patented Jan. 28, 1958.

port 68 by means of a collar 72 which is threadedly engaged in athreaded lower portion74 of the piston rod- 40, the collar 72 beingdisposed between the ears 70.

' The shaft 60 also extends through the ears-70 and is suitablyjournaled therein for both rotation and vertical sliding movement. Theshaft 60 also includes an elongated keyway 76. Positioned between thecars 70 and suitably keyed to the shaft 60 is a gear 78. Positionedabove the uppermost ear 70 and also keyed to the shaft 60 for verticalsliding movement is a crank 80. The crank 80 includes a-latch element 82which is engaged with a segment ring 84 having a plurality ofcircumferentially spaced notches 86 for receiving the latch 82. Thelatch 82 is pivotally mounted on a pivot pin 88 and normally seats inone of the notches 86. In order that the latch 88 may be selectivelymoved to an inoperative position, there is carried by the crank 80 asleeve 90 in which there is mounted a spring 92. Disposed within thespring 92 and connected to the latch member 82 is a pin 94 having abutton 96 on the upper end thereof. By depressing the button 96, thelatch member 82 is moved to an inoperative position and the crank 80 isfree to be rotated to rotate the shaft 60 whereby the gears 64 and 78may be rotated.

Slidably carried by the upper support 68 is an upper dog 98. The upperdog 98 includes a rack portion 100 which is meshed with the gear 78.

In the operation of the log dog assembly 14, a log, such as the log 16,to be sawed is positioned on the head block in abutment with the knee12. At this time the lower dog 58 and the upper dog 98 are separated,the lower dog 58 being in a lower point of travel out of the way of thelog 16 and the upper dog 98 being vertically elevated, as is bestillustrated in Figure 3. In the movement of the crank 80 will benecessary to properly position the dogs 58 and 98.

It is pointed out that the dogs 58 and 98 are disposed on the left sideof the slide bar 30, as is illustrated in Figure 4. If desired, thegears 64 and 78 may be made smaller or moved further away from the slidebar 30. In such event, the dogs 58 and 98 may be moved to the right ofthe slide bar 30 if it is so desired.

,. A resilient stop assembly 102. (Figures 2 and 4) is carried by theplate 24. The stop assembly 102 includes a stop member 104 having a stem106 slidably passing through the plate 24. A spring 108 is carried bythe stem 106. An angle member'110 is carried by event the dogs 58 and 98project farther enough away from the knee 12, it will not be necessaryto move in or out with respect to the supports 56 and 68. Thus once thelog 16 has been pushed against the knee 12, it is merely necessary forthe operator of the sawmill to turn the handle 52 to the desiredposition. This will result in the piston 38 moving downwardly so thatthe piston rod will also move downwardly to move the upper dog 98 intoengagement with the log 16. Once'the dog 98 engages the log 16, thedownward movement of the piston 38 will substantially stop and as aresult the cylinder 34 will move upwardly. This will result in theupward movement of the lower dog 58 to the position illustrated inFigure 1. Further movement of the piston 38 with respect to the cylinder34 will result in the effective clamping of the log 16. Inasmuch as theoperator merely has to turn the handle 52 to position the dogs 58 and98, it will be readily apparent that the operation of the log dogassembly 14 is extremely simple and requires no hard work on the part ofthe sawmill operator. After the log 16 has been fully sawed,'it isreleased from the head block 10 by turning the handle 52 in the oppositedirection. This will result in the simultaneous upper movement of thepiston 38 and the downward movement of the cylinder 34, so as to movethe dogs 58 and 98 apart.

In the event a log of a difierent size from the log 16 is to be mountedon the head block 10, it may be necessary to either advance or retractthe dogs 58 and 98. This is accomplished by merely releasing the latchmember 82 and rotating the crank 80 in any desired direction. Inasmuchas the crank 80 drives the shaft 60 which in turn drives the twogears 64and 78, it will be readily apparent that the dogs 58 and 98 are eitheradvanced or retracted simultaneously. Because of the ratio between thegears 64 and 78 and the rack portions 59 and-100, respectively, it willbe seen thatonlya slight the slide bar 30 in alignment with the stopmember 104.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it, is not desired to limit,the invention to the exact construction'and operation shown anddescribed, and accordingly, all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

Whatis claimed as new is'as follows:

1. A log dog assembly comprising a mounting bracket, a slide barsupported by said mounting bracket for limited vertical slidingmovement,'an upright fluid motor, said fluid motorincluding a cylindersecured to an upper end of said slide bar, a piston rod projectingdownwardly from said cylinder, a lower dog supported by and for up I anddown movement with said slide bar at the lower end of said slide bar, anupper dog slidably mounted for vertical movement on said slide bar, saidupper dog being connected to said piston rod.

2. A log dog assembly comprising a mounting bracket, a slide barsupported by said mounting bracket for limited vertical slidingmovement, an upright fluid motor, said fluid motor including a cylindersecured to an upper end of said slide bar, a piston rod projectingdownwardly from said cylinder, a lower dog supported by and for up anddown movement with said slide bar at the lower end of said slide bar, anupper dog slidably mounted for vertical movement on said slide bar, saidupper dog being connected to said piston rod, control means for saidfluid motor mounted on said mounting bracket.

I 3. A log dog assembly comprising a mounting bracket, a slide barsupported by said mounting bracket for limited vertical slidingmovement, an upright fluid motor, said fluid motorincluding a cylindersecured to an upper end of said slide bar, a piston rodprojecting'downwardly from said cylinder, a lower dog supported by and.for up and down movement with said slide bar at the lower end of saidslide bar, an upper dog slidably mounted for vertical movement on saidslide bar, said upper dog being connected to said piston rod, meansconnected to said upper and lower-dogs for simultaneously extending andretracting said upper and lower dogs relative'to said slide bar.

4. A log dog assembly comprising a mounting bracket, a slide barsupported by said mounting bracket for limited verticalsliding movement,an upright fluid motor, said fluid motor including a cylinder secured toan upper. end of said slide bar, a piston rod projecting downwardly fromsaid cylinder, a lower support carried by the lower end of said slidebar, a lower dog carried by said lower support for up and down movementwith said slide .bar, an upper support carried by said piston rod, saidupper support being vertically slidably mounted on said slide bar, anupper dog carried by said upper support, means connected to said upperand lower dogs for simultaneously extending and retracting said upperand lower dogs relative tosaid upper and lower supports andsaid slidebar.

5. A log dog assembly comprising a mounting bracket, a slide barsupported by said mounting bracket for limited vertical slidingmovement, an upright fluid motor, said fluid motor including a cylindersecured to an upper end of said slide bar, a piston rod projectingdownwardly from said cylinder, a lower support carried by the lower endof said slide bar, a lower dog carried by said lower support for up anddown movement with said slide bar, an upper support carried by saidpiston rod, said upper support being vertically slidably mounted on saidslide bar, an upper dog carried by said upper support, means connectedto said upper and lower dogs for simultaneously extending and retractingsaid upper and lower dogs relative to said upper and lower supports andsaid slide bar, said means including racks on said upper and lower dogs,a shaft carried by said mounting bracket for rotation and verticalsliding movement, gears connected to said shaft for rotation with saidshaft, said gears being meshed with said racks.

6. A log dog assembly comprising a mounting bracket, a slide barsupported by said mounting bracket for limited vertical slidingmovement, an upright fluid motor, said fluid motor including a cylindersecured to an upper end of said slide bar, a piston rod projectingdownwardly from said cylinder, a lower support carried by the lower endof said slide bar, a lower dog carried by said lower support for up anddown movement with said slide bar, an upper support carried by saidpiston rod, said upper support being vertically slidably mounted on saidslide bar, an upper dog carried by said upper support, means con-'nected to said upper and lower dogs for simultaneously extending andretracting said upper and lower dogs relative to said upper and lowersupports and said slide bar, said means including racks on said upperand lower dogs, a shaft carried by said mounting bracket for rotationand vertical sliding movement, gears connected to said shaft forrotation with said shaft, said gears being meshed 6 with said racks, oneof said gears being retained by said upper support for movementtherewith, said one gear being keyed on said shaft for relative slidingmovement.

7. A log dog assembly comprising a mounting bracket, a slide barsupported on said mounting bracket for limited vertical slidingmovement, an upright fluid motor, said fluid motor including a cylindersecured to an upper end of said slide bar, a piston rod projectingdownwardly from said cylinder, a lower support carried by the lower endof said slide bar, a lower dog carried by said lower support for up anddown movement with said slide bar, an upper support carried by saidpiston rod, said upper support being vertically slidably mounted on saidslide bar, an upper dog carried by said upper support, means connectedto said upper and lower dogs for simultaneously extending and retractingsaid upper and lower dogs relative to said upper and lower supports andsaid slide bar, said means including racks on said upper and lower dogs,a shaft carried by said mounting bracket for rotation and verticalsliding movement, gears connected to said shaft for rotation with saidshaft, said gears being meshed with said racks, one of said gears beingretained by said upper support for movement therewith, said one gearbeing keyed on said shaft for relative sliding movement, drive means forsaid shaft supported by said upper support.

References Cited in the file of this patent UNITED STATES PATENTS484,332 Martin et al Oct. 11, 1892 1,724,010 Ferris Aug. 13, 19291,772,052 Martin Aug. 5, 1930 2,626,640 Cahoon Ian. 27, 1953 2,661,779Saunders Dec. 8, 1953

